Index

#lua   #cheat sheet  

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Table of Content

condition

-- canVote = age > 18 ? true : false
canvote = age > 18 and true or false

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Strings

loops

i = 1
while (i <= 10) do
    io.write(i)
    i = i + 1
    if i == 8 then break end
end

tables

table are one base

table are one base and not zero base like many programming language

mytable = { ‘name_a’, ‘name_b’ }

for k, v in pairs(mytable) do print(k, v) end

print(mytable[1]) print(mytable[2])

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files

file = io.open("test.txt", "w+")
file:write("first line\n")
file:write("second line\n")

file:seek("set", 0)

print(file:read("*a"))

file:close()

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modules

├── lib
│   └── convert.lua
├── model_demo.lua

lib/convert.lua

local convert = {}

function convert.cm2in(cm)
    return 2.54 * cm
end

return convert

model_demo

convert_module = require("examples.lib.convert")  -- same directory

print(string.format("%f", convert_module.cm2in(2)))

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oop

Lua isn’t oop language We create object like with tables and metatables

Animal = {name="", color="black"}

function Animal:new(name)
    setmetatable({}, Animal)
    self.name = name

    return self
end

function Animal:toString()
    animal_str = string.format("%s %s", self.name, self.color)
    return animal_str
end

usage

spot = Animal:new(10)
print(spot.color)
print(spot:toString())